磁转变对La_(0.7)Ca_(0.3)MnO_3在T_c附近的输运性质的影响  

INFLUENCE OF MAGNETIC TRANSITION ON THE TRANSPORT PROPERTIES IN La 0.7 Ca 0.3 MnO 3 AROUND T c

作　　者：盛松[1] 吴柏枚[1] 杨东升[1] 李荐扬 周雅琴[2] 熊光成[2] 

机构地区：[1]中国科学技术大学物理系 [2]北京大学物理系

出　　处：《低温物理学报》1997年第6期427-431,共5页Low Temperature Physical Letters

基　　金：高等学校博士学科点专项科研基金

摘　　要：测量了Ｌａ０．７Ｃａ０．３ＭｎＯ３的热导和电阻，温度范围为７７～３００Ｋ．在２６０Ｋ，观察到电阻曲线上的金属－半导体转变的峰，热导曲线上有一个不大的斜率的变化．同时还发现在热导单调光滑下降曲线上２２０～２６０Ｋ热导有增加，电阻在２４０Ｋ有斜率的变化，我们讨论了这两种输运性质，认为这与材料在Ｔｃ附近复杂的磁行为相联系．he thermal conductivity and resistance of La 0.7 Ca 0.3 MnO 3 have been measured in temperatures range from 77K to 300K. A peak on resistance temperature curve indicating metal semiconductor transition and a slight change of slope on thermal conductivity temperature curve are observed at 260K. There are a small increase between 220￣260K on the smooth curve of thermal conductivity temperature, as well a change of slope at 240K on resistance temperature curve. It is suggested that two kind of transport properties were related with the complex magnetic behavior around T c .

关 键 词：输运性质 超导体 磁转变 LCMO TC 热导 

分 类 号：TM262[一般工业技术—材料科学与工程]